APA (7th ed.) Citation

Thomas, P., Thomas, D., & Whitman, W. (2010). Trees. Peter & Donna Thomas.

Chicago Style (17th ed.) Citation

Thomas, Peter, Donna Thomas, and Walt Whitman. Trees. Santa Cruz: Peter & Donna Thomas, 2010.

MLA (9th ed.) Citation

Thomas, Peter, et al. Trees. Peter & Donna Thomas, 2010.